Method for cooling a shaft furnace loading device

ABSTRACT

The invention concerns a method for cooling a shaft furnace loading device, said loading device being equipped with a ring-shaped rotary joint ( 40 ), provided with a fixed ring-shaped part ( 56 ) and a rotating ring-shaped part ( 46 ), for supplying cooling liquid to a rotating cooling circuit ( 36, 38 ). The invention is characterized in that it consists in feeding the joint ( 40 ) fixed part ( 56 ) with cooling liquid such that a leakage flow passes in a separating ring-shaped slot ( 58, 60 ) between the fixed part ( 56 ) and the rotating part ( 46 ) of the joint ( 40 ), to form therein a liquid joint. Said leakage flow is then collected and drained without passing through the cooling circuit ( 36, 38 ).

The invention relates to a process for cooling a device for charging ashaft furnace. A device for charging a shaft furnace of the typeconsidered in the invention comprises in particular a support casingmounted on the head of the furnace, loading equipment suspended in arotatable manner on the support casing, and at least one cooling circuitsupported by rotatable charging equipment and fed by a ring-shapedrotating connection device.

Such a charging device is described, for example, in Luxembourg patentapplication LU 80112. The charging equipment comprises a charging troughsuspended in a suspension cage, which is itself suspended in the supportcasing, in such a way as to be set in rotation, and which is traversedby a central feed channel for the trough. This suspension cage alsoforms a protection screen around the feed channel, which protects theimplementation devices located in the support casing, and in particularagainst the radiation of heat from the interior of the shaft furnace.The suspension cage for the distribution trough is provided with acooling circuit. This is supplied by a cooling liquid by means of aring-shaped rotating connection device, located around the feed channelfor the trough. The connection device comprises a rotating shell, whichis carried by the suspension cage, and a fixed yoke. This yoke iscarried by the support casing, and the rotating shell is arranged with adegree of play in the fixed yoke. Two ring-shaped throats located aboveare provided in the fixed yoke, in such a way as to juxtapose the outercylindrical surface of the rotating shell. A number of connection pipesfor the cooling circuit define the location of openings in the outercylindrical surface of the rotating shell opposite the two throats.Sealing devices, which are mounted along the length of the two edges ofeach throat, are supported on the outer cylindrical surface of therotating shell, with the aim of ensuring the sealing effect between therotating shell and the fixed yoke. It has been found that this type ofrotating connection, which in particular requires a relatively lowamount of play between the rotating shell and the fixed yoke so as toguarantee the seal, is hardly well-suited for a charging device for ashaft furnace. In a shaft furnace, the rotating shell and the fixed yokein fact risk suffering from very different thermal expansion, as well asmechanical stresses, which rapidly lead to the blockage of theconnection with low functional play. in addition to this, in theenvironment of a shaft furnace, it must always be assumed that therewill be substantial volumes of dust present. This dust will inevitablypenetrate between the rotating shell and the fixed yoke, where it risksincurring a blockage of the rotating connection or of destroying thesealing devices. It must also be borne in mind that the sealing devicesare in contact with a shell which is quite hot, which is hardlyfavourable to them. It is therefore not surprising that a rotatingconnection system of this type has never in practice been applied to ashaft furnace.

Accordingly, in 1982, the company of Paul Wurth S. A. proposed a coolingarrangement for a charging installation of a blast furnace withoutsealing devices. This cooling arrangement, which is described in detailin patent application EP 0 116 142, has been installed in numerous blastfurnace charging installations throughout the world. It is characterisedby a ring-shaped trough, which is supported by a shell above therotating cage, which is gravity-fed with cooling water. For thispurpose, a cooling water feed duct is integrated in the support casingand features, above the ring-shaped trough, at least one openingallowing for the gravity circulation of the cooling water in thering-shaped trough in rotation with the suspension cage. The latter isconnected to several cooling coils which equip the rotating cage. Thesecoils are outlet ducts, which empty into a ring-shaped collectorsupported by the lower edge of the support casing. The waterconsequently flows by gravity, starting from a fixed-position feed pipein rotation, into the ring-shaped trough in rotation, passing by gravitythrough the cooling coils mounted on the rotating cage, and then iscollected in the lower fixed-position collector, and evacuated on theoutside of the support casing. This water circulation system ismonitored by level sensors connected to the ring-shaped trough and thelower collector. In the ring-shaped trough, the level is adjusted insuch a way as to be constantly between a minimum level and a maximumlevel. If the level drops as far as the minimum level, the feed outletof the ring-shaped trough is increased, so as to guarantee theappropriate feed to the coils. If the level rises as far as the maximumlevel, the feed outlet of the ring-shaped trough will be reduced, so asto avoid overflow from the ring-shaped trough.

A disadvantage of the 1982 cooling arrangement is that the gases fromthe blast furnace come in contact with the cooling water in thering-shaped trough. Because these blast furnace gases are heavily ladenwith dust, substantial quantities of dust pass into the cooling water.This dust forms sludges in the ring-shaped trough, which pass into thecooling coils and risk blocking them. In this context it is appropriateto note, inter alia, that the pressure available to cause the water topass through the coils is determined essentially by the heightdifferential between the ring-shaped trough and the lower collector.

The present invention, such as defined in Claim One, achieves asignificant reduction of the risk of penetration of the dust into thecooling circuit.

The process according to the invention relates more specifically to adevice for charging a shaft furnace, comprising: a support casingmounted on the head of the furnace, charging equipment suspended inrotatable fashion in the support casing, a cooling circuit supported bythe rotating charging equipment in such a way as to induce rotation inthe latter, as well as a ring-shaped rotating connection device, thisconnection device comprising a fixed part and a rotating part, capableof turning with the rotating charging equipment, the rotating part beingseparated from the fixed part by means of a ring-shaped separation gapso as to allow for relative rotation. In a known manner, the fixed partof the connection device is fed with a cooling liquid, which passes intothe rotating part of the connection device where it feeds the coolingcircuit, so as then to be evacuated at the outlet of the cooling circuiton the outside of the support casing. By contrast with arrangements ofthe state of the art, however, there is no attempt to ensure the perfectsealing of the turning connection, such as provided for, for example,under patent application LU 80112, nor to avoid leaks from the turningconnection by means of a system of level sensors, such as is providedfor, for example, in patent application EP 0116142. In fact, accordingto the invention, the feed of a cooling liquid of the turning connectionis effected in such a way that a leakage outlet passes through thering-shaped separation gap, so as to form therein a liquid joint, thisleakage outlet being collected and evacuated outside the support casingwithout passing through the cooling circuit. In other words, the coolingliquid is used to plug the ring-shaped separation gap, which must existbetween the rotating and fixed parts of the rotating connection so as toallow for rotation to take place, and which allows for the interior ofthe cooling circuit to be in communication with the furnacesurroundings. The leak rate, which has formed this liquid joint, is thencollected and evacuated directly outside the support casing, withoutpassing through the cooling circuit. The result of this is that the dustsludges formed in the gap no longer pass through the cooling circuit andtherefore do not incur the risk of blockage.

In most cases, it will be of advantage to provide the connection devicewith elements which are capable of creating an additional charge loss atthe level of the ring-shaped separation gap, in such a way that the feedpressure of the cooling liquid may be perceptibly higher than thecounter-pressure which prevails in the support casing, withoutgenerating any too substantial leak rate. In other words, the inventionallows for the first time for a cooling circuit for rotating chargingequipment to be fed with suppression capability. This not being furtherlimited from the point of view of feed pressure, it is plainly possibleto create cooling circuits of higher performance. It will also beappreciated that the leak rate which passes through those elements whichare prone to incur a loss in supplementary pressure (such as fittings,elastomer joints, labyrinth joints, etc.) guarantees a cooling effect, acertain degree of lubrication, and the constant cleaning of theseelements, which undoubtedly has a beneficial effect on their servicelife.

In a first embodiment, the connection device consists of a ring-shapedblock carried by the support casing, and delimited by two cylindricalsurfaces, as well as a ring-shaped channel, carried by the loadingequipment and delimited by two cylindrical surfaces. The ring-shapedblock, fixed in rotation, penetrates into the ring-shaped channel insuch a way that the juxtaposed cylindrical surfaces delimit tworing-shaped spaces which form part of said ring-shaped separation gap.The ring-shaped channel is provided to advantage with overflow aperturesconnected to the pipes for evacuating the leak rate. So as to create anadditional loss of charge, which reduces the leak rate when the coolingwater feed pressure is increased, provision is made between the twojuxtaposed cylindrical surfaces, below the overflow apertures, forelastomer ring-shaped joints, such as lip joints. The ring-shaped block,which is carried by the support casing, comprises to advantage a numberof passages which allow for communication between the two ring-shapedspaces, in such a way that there is pressure equilibrium between the tworing-shaped spaces.

According to a second embodiment, the connection device comprises aring, provided with a ring-shaped front surface fixed in rotation, aswell as a ring-shaped channel of one piece wit the charging equipment.The ring is located in the ring-shaped channel in such a way that itsfront ring-shaped surface is positioned opposite a ring-shaped surfacein the ring-shaped channel, a ring-shaped gap separating the twojuxtaposed ring-shaped surfaces. A set of fittings is then arrangedbetween the two ring-shaped surfaces, so as to create an additional lossof charge in said separation ring. The ring is to advantage mounted insuch a way that it can undergo translation parallel to the axis ofrotation, in order for it to be able to exercise a certain amount ofpressure on the set of fittings. In a first embodiment, the ring issupported by compensators, in such a way as to be able to undergo slightdisplacement parallel to the axis of rotation. In a second embodiment,the ring is connected with the aid of a sliding connection to a fixedring-shaped block, in such a way as to be able to slide parallel to theaxis of rotation.

According to another embodiment, the ring-shaped separation gap forms atleast one labyrinth joint. In this case, the connection device comprisesto advantage a ring-shaped block which is carried by the support casingand delimit laterally by two staged ring-shaped surfaces, as well as aring-shaped channel, carried by the charging equipment and delimitedlaterally by two staged ring-shaped surfaces, in a complementary manner.The ring-shaped block then penetrates into the ring-shaped channel insuch a way that the two juxtaposed staged surfaces interact so as toform a labyrinth joint, which forms part of said ring-shaped separationgap. As already described previously, the ring-shaped channel isprovided to advantage with overflow apertures connected to the pipes forevacuating the leak rate, and located above the labyrinth joint, and thering-shaped block, carried by the support casing, comprises to advantagepassages which allow for communication between the two ring-shapedspaces.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages can be identified from the detaileddescription of the advantageous embodiment presented by way ofillustration hereinafter, making reference to the appended drawings.These show:

FIG. 1 is a vertical section through a charging device for a shaftfurnace, suitable for cooling by the process according to the invention;

FIG. 2 is a vertical section through a ring-shaped rotating connectiondevice fitted to the charging equipment of a shaft furnace from FIG. 1;

FIG. 3 is another vertical section through the ring-shaped rotatingconnection device fitted to the charging equipment of a shaft furnace ofFIG. 1;

FIG. 4 is a vertical section through a variant design of the rotatingconnection device;

FIG. 5 is another vertical section through the variant design of therotating connection device according to FIG. 4;

FIG. 6 is a vertical section through a second embodiment of the rotatingconnection device;

FIG. 7 is another vertical section through the variant design of therotating connection device according to FIG. 6;

FIG. 8 is a vertical section through a third embodiment of the rotatingconnection device;

FIG. 9 is a plan view of the rotating connection devices according toarrow A in FIGS. 2, 4, 6 and 8;

FIG. 10 is a simplified horizontal section according to the arrows B—Bof FIGS. 2, 4, 6 and 8;

FIG. 11 is a simplified horizontal section according to the arrows C—Cof FIGS. 6 and 8.

FIG. 1 shows a schematic representation of a charging installation for ashaft furnace, provided with a distribution trough 10. The latter is setin rotation about the central axis of the shaft furnace, indicated byreference number 8. An installation of this type is described in detail,for example, in patent U.S. Pat. No. 3,880,302. It is important to note,however, that the present invention relates in a general manner to anycharging installation for a shaft furnace, comprising charging equipmentwhich is suspended in such a way as to be able to be set n motion aboutan axis. It is certainly not limited to an installation of the typedescribed in the patent U.S. Pat. No. 3,880,302.

The trough 10 is suspended with the aid of a suspension and movementinitiation device, referred to overall by the number 12, in a supportcasing 14 mounted on the shaft furnace. This device 12 comprises atoothed crown element 16 which serves to set in rotation a hell element18 about a central feed channel 20, fixed in rotation. The movement isinitiated with the aid of a motor, not shown. As described in the patentU.S. Pat. No. 3,880,302, the suspension and movement initiation device12 may, in addition, comprise a mechanism allowing for angularadjustment of the trough 10 by pivoting about a horizontal axis.

The support casing 14 is delimited laterally, with the rotatable shellelement 18, by a ring-shaped chamber 22, in which is located, forexample, the mechanism for pivoting the trough 10. The rotating shell 18is carried by a cage 24, in which the trough 10 is suspended with theaid of trunnions 26. This cage 24 also functions as a screen between thelower edge of the rotating shell 18 and the lower edge 25 of the supportcasing 14, in such a way as to separate the ring-shaped chamber 22 fromthe interior of the furnace.

It is evident that the parts most exposed to the radiant heat of thefurnace are the walls of the cage 24. So as to protect these walls fromhigh temperatures, and to avoid them passing the heat on, either byconduction or by radiation, to other elements of the suspension andmovement initiation device 12, this cage 24 is provided with severalcooling circuits, in which a cooling liquid is circulated, such aswater. In FIG. 1 these circuits are represented in schematic form bycooling box structures 28, 30, 32, 34. The latter contain to advantagebaffles or pipes (not shown) which allow the cooling water to circulatealong the walls of the cage 24. The box structures 28, 30, 32, 34 areconnected by means of pipework 36, 38, with a rotating ring-shapedconnection device, indicated overall by the reference number 40. Thelatter will be described in detail hereinafter with the aid of FIGS. 2and 3. In FIG. 1 the evacuation of the water of the cooling circuits 28,30, 32, 34, can again be seen, which is effected by means of pipes 40,42, into a ring-shaped collector 44 fixed to the lower edge 25 of thesupport casing 14. From the ring-shaped collector 44, the cooling wateris initially evacuated by evacuation pipework 46, 48, to the outside ofthe support casing 14. In addition to the cooling circuits 28, 30, 32,34, shown in FIG. 1, the trough 10 itself can be provided with a coolingcircuit which is fed for preference at the suspension cage 24 via thesuspension trunnions 26. This additional circuit can be equipped withits own connection to the ring-shaped rotating device 40, or connectedto one of the cooling circuits 28, 30, 32, 34.

A more detailed description will now be given, with the aid of FIGS. 2and 3, of a first embodiment of the ring-shaped rotating connectiondevice 40. This comprises essentially a fixed part, connected to astationary feed circuit (represented by a pipe 44) and a rotating partconnected to the cooling circuits 28, 30, 32, 34 via the pipe 36. Therotating part is essentially a ring-shaped trough 46, which defines aring-shaped channel 47, which is delimited laterally by two coaxialcylindrical surfaces. One of the two cylindrical surfaces is defined bythe outer wall of the shell element 18, and the other is defined by acrown element 48, surrounding the shell element 18. The upper edges ofthe shell 18 and the crown element 48 slide, during the rotation of thetrough 10, each in a ring-shaped groove 50, 52, arranged in a fixedelement of the outer body 14, in such a way as to create a first pair ofring-shaped gaps 54, 55, between the fixed part and the rotating part.This first pair of ring-shaped gaps 54, 55, is aimed at retarding thepenetration of dust-laden gas into the ring-shaped trough 46. The fixedpart of the connection device 40 consists essentially of a ring-shapedblock 56 fixed to the support casing 14, and delimited on the outside bytwo cylindrical surfaces. This ring-shaped block 56 is located in thering-shaped channel 47 in such a way that its outer cylindrical surfacesdelimit, together with the juxtaposed cylindrical surfaces of thechannel 47, a second pair of ring-shaped gaps 58, 60, between the fixedpart and the rotating part of the connection device 40. The ring-shapedblock 56 comprises at least one passage aperture 62, which providescommunication between a ring-shaped chamber 64 and a ring-shaped feedchannel 66, into which the fixed feed pipes 44 empty. As a comparison ofFIGS. 9 and 10 shows, the mouths of four feed ducts 44 in thering-shaped feed channel 66, are considerably off-centre in relation tothe passage apertures 62. The connection pipes 36, 38, of the coolingcircuits 28, 30, 32, 34, feature a mouth outlet 68 in the base of thechannel 47.

So as to cool the rotating cage 24, the ducts 44 are fed with coolingwater. This water passes into the ring-shaped channel 66, which it mustpass through before leaving via the passages 62. It will be noted thatthe water which passes through the ring-shaped channel 66 fulfils therole of a thermal barrier between the central supply channel 20 and theupper plate of the support casing 14, and also ensures the cooling ofthe suspension device 12. The water then flows across the ring-shapedchamber 64 of the fixed block 56 in the ring-shaped channel 47 of thetrough 46. It passes through the apertures 68 in the base of the channel47 into the connecting pipes 36, 38, of the cooling circuits 28, 30, 32,34. At the outlet of these circuits the cooling water flows via thepipes 40, 42, into the ring-shaped collector 44, which is again fixed inrotation, so as to be evacuated via the evacuation pipes 46, 48, to theoutside of the body structure 14.

According to an important feature of the invention, the feed of acooling liquid for the rotating connection 40 is effected in such a waythat any leak rate passes through the two ring-shaped gaps 58, 60, toform therein a liquid joint. This leak rate is then collected andevacuated outside the support casing 14 without passing through one ofthe cooling circuits 28, 30, 32, 34. The means used to collect the leakrate in the two ring-shaped gaps 58, 60, are described with the aid ofFIG. 3. Located in the crown element 48 is at least one overflowaperture 70. A ring-shaped outlet 71 in the ring-shaped block 56facilitates the flow of the leak rate through the overflow apertures 70.The overflow aperture 70 communicates via a channel 72 with anevacuation pipe 74. In FIG. 1, the evacuation pipe 74, which opens intothe ring-shaped collector 44 is shown in the right-hand part of theFigure. In FIGS. 2 and 3, it can again be seen that each of the tworing-shaped gaps 58, 60, is provided with a joint 76, 78, located belowthe level of the overflow aperture 70. These joints 76, 78, are forpreference lipped elastomer joints, the aim of which is to create anadditional charge loss at the level of the two ring-shaped gaps 58, 60,in such a way that the feed pressure of the cooling liquid can beperceptibly higher than the counter-pressure pertaining in the furnace,without generating an excessive leak rate. It is important, as aconsequence, to note that, when functioning normally, these elastomerjoints 76, 78, are not intended to avoid leaks, but to limit the leakrate to an acceptable level. In FIG. 3, it can again be seen that thering-shaped gap 58 communicates with the ring-shaped gap 60 by means ofat least one passage 80 through the ring-shaped block 56. These passages80 allow for the leak water outlet to be evacuated, which passes throughthe ring-shaped gap 60. A ring-shaped outlet 81 in the ring-shaped block56 facilitates the flow of this outlet through the passages 80.

It will be appreciated that the elastomer joints 76, 78, are constantlycooled, “lubricated”, and cleaned by the leak rate which passes belowthem. This leak rate carries away all the solid matter which might beintroduced through the two ring-shaped gaps 58, 60. In order also toprotect the two ring-shaped gaps 58, 60, against the accumulation ofdust, it is recommended that a clean gas be injected into the furnacevia the joints 54, 55. In FIGS. 2 and 3 a ring-shaped channel 82 can beseen, which allows for a gas to be injected, such as nitrogen, forexample, through the joint 55 and into the shell 18.

A variant design of the rotating ring-shaped connection device isdescribed with the aid of FIGS. 4 and 5. This device is distinguishedfrom the device in FIGS. 2 and 3 essentially by the fact that the secondpair of ring-shaped gaps 58, 60, are designed in the form of labyrinthjoints 58′, 60′. So as to be able to introduce the ring-shaped block 56′into the ring-shaped channel 47′, so as to form the two labyrinth joints58′, 60′, staged trapezoidal sections have been applied to the block 56′and the channel 47′, which interact so as to form the two labyrinthjoints 58′, 60′. It remains to be noted that, at the level of theoverflow aperture, provision has been made in the block 56′ forring-shaped throat elements 84, 86, so as to facilitate the flow of asubstantial leak rate. These ring-shaped throat elements are connectedby at least one passage 70′, which fulfils the same function as thepassage 70 of the device in FIGS. 2 and 3. It will be noted that theleak rate which occurs via the two labyrinth joints 58′, 60′, cools theelements which form the labyrinth joints, avoids the penetration of gasinto the cooling circuit, carries away the solid matter which mightother infiltrate into the labyrinth joints, and purges the dust sludgewhich might form in the channel 47′ above the two joints 58′, 60′.

Another embodiment of a ring-shaped rotating connection device isdescribed with the aid of FIGS. 6 and 7. This device is distinguishedfrom the device in FIGS. 2 and 3 essentially by the fact that the secondpair of ring-shaped gaps 58, 60, are replaced by a single frontalring-shaped gap 90, which separates one ring-shaped frontal face of aring element 92, fixed in rotation, from a frontal ring-shaped surfaceof a ring element 94, mounted in the trough 46. Mounted between the tworings 92 and 94 are two fittings 96, 98, in such a way that they delimita ring-shaped space between them. The purpose of these fittings 96, 98,is to create an additional loss of charge at the level of the frontalgap 90, in such a way that the feed pressure of the cooling liquid maybe perceptibly higher than the counter-pressure prevailing in thechannel 47, but without generating an excessive leak rate. It isimportant as a consequence to note that, when these devices 96, 98, arefunctioning normally, their purpose is not to avoid leaks, but to limitthe leak rate to an acceptable level. The leak rate which passes belowthese devices 96, 98, flows into the ring-shaped channel 47. In FIG. 7,it can be seen that the latter is provided, at the level of its base, ina cavity below the ring 94, with at least one aperture 100 in anevacuation pipe 74′, which opens, like its equivalent, the evacuationpipe 74 in FIG. 1, into the ring-shaped collector 44. The main outlet ofthe cooling water passes through the mouths 102 into the ring element 94into the connecting pipes 36, 38, of the cooling circuit. The ringelement 92 is connected to a ring-shaped block 56″ (which corresponds tothe upper part of the ring-shaped block 56 in FIGS. 2 and 3), with theaid of two co-axial compensators 104, 106. These latter elements allowthe ring element 92 to be placed on the ring element 94, and to ensure acertain degree of compression of the fittings 96, 98. So as to ensureadequate compression on the fittings 96, 98, it is in principle theweight of the ring element 92 which is applied. Moving across aring-shaped space 108, delimited by the two co-axial compensators 104,106, the cooling water passes into the communications apertures 110arranged in the ring element 92. FIG. 11 shows in sectional form thecommunication apertures 110, oblong in shape, as well as the mouths 102of the connecting pipes 36, 38, of the cooling circuits 28, 30, 32, 34.The four black dots in FIG. 11 indicate the locations of four mouths 102of evacuation pipes 74′ for the leak rate. It remains to be noted thatthe two large compensators 104 and 106 may possibly be replaced bysmall-diameter compensators, directly extending the passages 62 into aring-shaped chamber arranged in the ring element 92.

An additional embodiment of a ring-shaped rotating connection device isdescribed with the aid of FIG. 8. This device is distinguished from thedevice in FIGS. 6 and 7 essentially due to the fact that thecompensators 104, 106 are replaced by a sliding ring-shaped connector112, arranged between a ring element 92′, which is the equivalent of thering element 92, and a ring-shaped block 56″, which is the equivalent ofthe ring-shaped block 56″. So as to provide this sliding ring-shapedconnection 112, the ring element 92′ is provided with a ring-shapedchamber 114, in which is located the ring-shaped end 116 of the block56″. Elastomer joints 118, 120 improve the sealing capacity of thesliding joint 112. It will be appreciated that these elastomer joints118, 120, are subjected to much less stress than the elastomer joints76, 78, of the device in FIGS. 2 and 3, since the ring element 92′ isblocked in rotation. So as to ensure adequate compression of thefittings 96, 98, recourse is made in principle to the weight of the ring92′. The possibility is not excluded, however, of governing thiscompression force with the aid of spring (not shown), which are fittedbetween the ring element 92′ and the ring-shaped block 56″. It remainsto be noted that the pressure of the water in the chamber 114 alsocontributes towards providing a slight increase in the compression ofthe fittings 96, 98. It will, however, always be necessary to guaranteea residual leak rate, sufficient to cool, “lubricate”, and clean thefittings and to purge all the dust which might be introduced into thechannel 47.

What is claimed is:
 1. A process for cooling a charging device of ashaft furnace, said charging device including a support casing mountedon said shaft furnace, charging equipment suspended in a rotatablemanner in said support casing, at least one cooling circuit carried bysaid charging equipment and a ring-shaped rotating connection device,said connection device including a fixed ring-shaped part immobile inrotation, and a rotating ring-shaped part in rotation with said chargingequipment, said rotating ring-shaped part being separated from saidfixed ring-shaped part by a ring-shaped separation gap; said processcomprising: a) feeding said fixed ring-shaped part of said connectiondevice with a cooling liquid flow; b) passing a first sub-flow of saidcooling liquid flow as a leakage flow through said ring-shapedseparation gap so as to form therein a liquid joint, collecting saidleakage flow and evacuating said leakage flow out of said support casingwithout passing said leakage flow through said at least one coolingcircuit; and c) transferring a second sub-flow of said cooling liquidflow from said fixed ring-shaped part onto said rotating ring-shapedpart of said connection device, passing said second sub-flow as acooling flow through said at least one cooling circuit before evacuatingsaid second sub-flow out of said support casing.
 2. The processaccording to claim 1, wherein said support casing is maintained under acounter-pressure; and step a) comprises feeding said fixed ring-shapedpart of said connection device with a cooling liquid flow at a feedpressure that is higher than said counter-pressure; and wherein step b)comprises limiting said leakage flow by creating a loss of charge at alevel of said ring-shaped gap.
 3. The process according to claim 1,wherein said connection device includes a ring-shaped block, which iscarried by said support casing and delimited by two cylindricalsurfaces, and a ring-shaped channel, which is carried by said chargingequipment and delimited by two cylindrical surfaces, said ring-shapedblock penetrating into said ring-shaped channel so that said cylindricalsurfaces of said ring-shaped block and said ring-shaped channel arejuxtaposed and co-operate to delimit two ring-shaped spaces in saidring-shaped channel; and wherein step b) comprises passing said leakageflow through said two ring-shaped spaces so as to form a liquid jointbetween said juxtaposed cylindrical surfaces of said ring-shaped blockand said ring-shaped channel.
 4. The process according to claim 3,wherein step b) further comprises evacuating said leakage flow throughoverflow apertures provided in said ring-shaped channel; and collectingsaid leakage flow by means of evacuation pipes connected to saidoverflow apertures.
 5. The process according to claim 3, wherein step b)further comprises establishing a pressure equilibrium between said tworing-shaped spaces by means of passages in said ring-shaped block. 6.The process according to claim 4, wherein in step b) said leakage flowis limited by means of ring-shaped lip joints arranged between saidjuxtaposed cylindrical surfaces below said overflow apertures.
 7. Theprocess according to claim 1, wherein said connection device includes aring element, which is fixed in rotation and provided with a ring-shapedfrontal surface, and a ring-shaped channel, which is carried by saidrotating-charging equipment and provided with a ring-shaped bottomsurface, said ring element penetrating in said ring-shaped channel sothat a ring-shaped frontal surface of said ring-shaped channel and saidring-shaped bottom surface are separated by a ring-shaped separationgap; and wherein step b) comprises passing said leakage flow throughsaid ring-shaped separation gap so as to form a liquid joint betweensaid ring-shaped frontal surface and said ring-shaped bottom surface. 8.The process according to claim 7, wherein in step b) the leakage flowthrough said ring-shaped separation gap is limited by means of a set offittings arranged between said ring-shaped frontal surface and saidring-shaped bottom surface.
 9. The process according to claim 8, whereinsaid ring element is mounted in such a way as to be axiallydisplaceable; and wherein step b) comprises placing said set of fittingsunder axial pressure between said ring-shaped frontal surface and saidring-shaped bottom surface.
 10. The process according to claim 8,wherein said ring element is mounted on compensators in such a way as tobe axially displaceable; and wherein step b) comprises placing said setof fittings under axial pressure between said ring-shaped frontalsurface and said ring-shaped bottom surface.
 11. The process accordingto claim 8, wherein said connection device includes a ring-shaped blocksupported by said support casing, and said ring element is connected tosaid ring-shaped block by means of a sliding connection in such a way asto be axially displaceable; and wherein step b) comprises placing saidset of fittings under axial pressure between said ring-shaped frontalsurface and said ring-shaped bottom surface.
 12. The process accordingto claim 1, wherein step b) said leakage flow is limited by means of alabyrinth joint within said ring-shaped separation gap.
 13. The processaccording to claim 1, wherein said connection device includes aring-shaped block, which is carried by said support casing and laterallydelimited by two staged ring-shaped surfaces, and a ring-shaped channel,which is carried by said charging equipment and laterally delimited bytwo complementarily staged ring-shaped surfaces, said ring-shaped blockpenetrating into the ring-shaped channel in such a way that said stagedsurfaces are juxtaposed and co-operate to form labyrinth joints; andwherein step b) further comprises passing said leakage flow through saidlabyrinth joints.
 14. The process according to claim 13, wherein step b)further comprises evacuating said leakage flow through overflowapertures provided in said ring-shaped channel; and collecting saidleakage flow by means of evacuation pipes, which are connected to saidoverflow apertures.